Development status and trend of reverse time migration

Reverse time migration(RTM)is more applicable for the imaging of complex structures than one-way wave-equation migration and Kirchhoff integral migration.Based on two-way wave-equation, extrapolating wavefields in reverse time domain and applying imaging conditions to extract the imaging values,we can gain reverse time migration data volume.The imaging results of salt flanks and subsalt structures by applying reverse imaging are better than oneway wave-equation migration.However,since reverse time imaging adopts finite difference algorithm and needs to store large amount of source wavefield data,its computation cost is high,which causes it not suitable for processing huge amount of seismic data.In addition, the low-frequency noise caused by crosscorrelation imaging conditions also puzzles the practicality of reverse time migration. Based on summarizing and analyzing the technical progress of reverse time migration techniques as well as its development strategies of foreign geophysical companies,combining with development status,we analyzed the future development trend and research focus of reverse time migration.We think that further improving the computation efficiency is still an important development direction of reverse time migration in future few years,elastic wave reverse time migration and anisotropic reverse time migration will be paid more attention to.